Nortel Circuit Card Installation Manual page 597

Note: Pseudo-answer supervision is provided by near-end at expiration
of end-of-dial timer. Where no far-end answer supervision is provided,
the party at the far-end hangs up after recognizing near-end call
termination.
Outgoing automatic, incoming dial operation
Incoming calls
When the NT8D14 Universal Trunk card is seized by the far-end on an
incoming call, a low-resistance loop is placed across the tip and ring leads.
Addressing is then sent by the far-end in the form of battery-ground or loop
pulses, or DTMF tones. The trunk is released at the far-end when the loop is
opened. When the near-end detects an open loop, it returns to a normal state.
See Figure 134 on
Outgoing calls
When seized as a dial-selected outgoing trunk, the near-end places the battery
on the tip and ground on the ring. This alerts the far-end of the seizure. The
far-end responds with a low resistance across the tip and ring leads.
See Figure 136 on
NT8D14 Universal Trunk card
page 599 and Figure 135 on
page 601 and Figure 137 on
Circuit Card
Page 597 of 906
page 600.
page 602.
Description and Installation